The present invention pertains to the field of micro-electro-mechanical-system (MEMS) devices. More particularly, the present invention relates to a MEMS mirror device.
A MEMS device is a micro-sized mechanical structure having mechanical devices fabricated, for example, by using conventional integrated circuit (IC) fabrication methods. One type of MEMS device is a microscopic gimbaled mirror device. A gimbaled mirror device includes a mirror component, which is suspended off a substrate, and is able to pivot about two axes. Motion is caused by electrostatic actuation. Electrostatic actuation creates an electric field that causes the mirror component to pivot. By allowing the mirror component to pivot in two axes, the mirror component is capable of having an angular range of motion in which the mirror component can redirect light beams to varying positions across a two-dimensional surface.
FIG. 1 shows an example of a MEMS gimbaled mirror device used to redirect light beams in an optical switch. Light beams from fibers 1 located in input fiber array 2 are input to the optical switch and travel through input lens array 3. Each beam is then reflected from a mirror located on input movable mirror array 4 to another mirror on output mirror array 5. The light beams then travel through lens array 6 to output fiber array 7. Thus, a given beam is switched from an input fiber of input fiber array 2 to an appropriate output fiber of output fiber array 7 by being redirected by mirror arrays 4 and 5.
For this type of optical networking application, the intensity of the signals at the input or the output of the switch may be monitored to verify that the network is operating properly. Thus, a fiber tap array 9 is optically coupled to the fibers of input fiber array 2. The light beams traveling through each fiber of fiber array 2 are then sampled by diverting a portion of the beams through fiber tap array 9 to receivers in electrical receiver array 91. The receivers in receiver array 91 may convert the optical signals into digital electronic signals, or an optical switch may be used to multiplex the signals into a single electrical receiver. A disadvantage of this approach is that an individual tap fiber in tap array 9 must be connected to each input fiber of input array 2. Another disadvantage is that an individual receiver must be connected to each tap fiber. Therefore, the cost of monitoring the signals using this approach can be very high.
An optical cross-connect with integrated optical signal tap is disclosed. In one embodiment, the switch includes two or more optical fiber input ports, lenses to produce collimated beams, one or more optical taps to couple a portion of the optical power from one or more input ports to one or more sample ports, movable mirrors to connect any input port with any output port, two or more optical fiber output ports, and lens to couple collimated beams into the output ports.